import {
    wrapIn,
    setBlockType,
    chainCommands,
    toggleMark,
    exitCode,
    joinUp,
    joinDown,
    lift,
    selectParentNode,
} from "../core/commands";
import {
    wrapInList,
    splitListItem,
    liftListItem,
    sinkListItem,
} from "../core/schema-list";
import { undo, redo } from "../core/history";
import { undoInputRule } from "../core/inputrules";

const mac =
    typeof navigator != "undefined" ? /Mac/.test(navigator.platform) : false;

// :: (Schema, ?Object) → Object
// Inspect the given schema looking for marks and nodes from the
// basic schema, and if found, add key bindings related to them.
// This will add:
//
// * **Mod-b** for toggling [strong](#schema-basic.StrongMark)
// * **Mod-i** for toggling [emphasis](#schema-basic.EmMark)
// * **Mod-`** for toggling [code font](#schema-basic.CodeMark)
// * **Ctrl-Shift-0** for making the current textblock a paragraph
// * **Ctrl-Shift-1** to **Ctrl-Shift-Digit6** for making the current
//   textblock a heading of the corresponding level
// * **Ctrl-Shift-Backslash** to make the current textblock a code block
// * **Ctrl-Shift-8** to wrap the selection in an ordered list
// * **Ctrl-Shift-9** to wrap the selection in a bullet list
// * **Ctrl->** to wrap the selection in a block quote
// * **Enter** to split a non-empty textblock in a list item while at
//   the same time splitting the list item
// * **Mod-Enter** to insert a hard break
// * **Mod-_** to insert a horizontal rule
// * **Backspace** to undo an input rule
// * **Alt-ArrowUp** to `joinUp`
// * **Alt-ArrowDown** to `joinDown`
// * **Mod-BracketLeft** to `lift`
// * **Escape** to `selectParentNode`
//
// You can suppress or map these bindings by passing a `mapKeys`
// argument, which maps key names (say `"Mod-B"` to either `false`, to
// remove the binding, or a new key name string.
export function buildKeymap(schema, mapKeys) {
    let keys = {},
        type;
    function bind(key, cmd) {
        if (mapKeys) {
            let mapped = mapKeys[key];
            if (mapped === false) return;
            if (mapped) key = mapped;
        }
        keys[key] = cmd;
    }

    bind("Mod-z", undo);
    bind("Shift-Mod-z", redo);
    bind("Backspace", undoInputRule);
    if (!mac) bind("Mod-y", redo);

    bind("Alt-ArrowUp", joinUp);
    bind("Alt-ArrowDown", joinDown);
    bind("Mod-BracketLeft", lift);
    bind("Escape", selectParentNode);

    if ((type = schema.marks.strong)) {
        bind("Mod-b", toggleMark(type));
        bind("Mod-B", toggleMark(type));
    }
    if ((type = schema.marks.em)) {
        bind("Mod-i", toggleMark(type));
        bind("Mod-I", toggleMark(type));
    }
    if ((type = schema.marks.code)) bind("Mod-`", toggleMark(type));

    if ((type = schema.nodes.bullet_list))
        bind("Shift-Ctrl-8", wrapInList(type));
    if ((type = schema.nodes.ordered_list))
        bind("Shift-Ctrl-9", wrapInList(type));
    if ((type = schema.nodes.blockquote)) bind("Ctrl->", wrapIn(type));
    if ((type = schema.nodes.hard_break)) {
        let br = type,
            cmd = chainCommands(exitCode, (state, dispatch) => {
                dispatch(
                    state.tr.replaceSelectionWith(br.create()).scrollIntoView()
                );
                return true;
            });
        bind("Mod-Enter", cmd);
        bind("Shift-Enter", cmd);
        if (mac) bind("Ctrl-Enter", cmd);
    }
    if ((type = schema.nodes.list_item)) {
        bind("Enter", splitListItem(type));
        bind("Mod-[", liftListItem(type));
        bind("Mod-]", sinkListItem(type));
    }
    if ((type = schema.nodes.paragraph))
        bind("Shift-Ctrl-0", setBlockType(type));
    if ((type = schema.nodes.code_block))
        bind("Shift-Ctrl-\\", setBlockType(type));
    if ((type = schema.nodes.heading))
        for (let i = 1; i <= 6; i++)
            bind("Shift-Ctrl-" + i, setBlockType(type, { level: i }));
    if ((type = schema.nodes.horizontal_rule)) {
        let hr = type;
        bind("Mod-_", (state, dispatch) => {
            dispatch(
                state.tr.replaceSelectionWith(hr.create()).scrollIntoView()
            );
            return true;
        });
    }

    return keys;
}
